Hair straightener



FIG. 1 is a perspective view of a hair straightener showing my new design;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a rear elevation view thereof;

FIG. 4 is a left side elevation view thereof;

FIG. 5 is a right side elevation view thereof;

FIG. 6 is a top plan view thereof;

FIG. 7 is a bottom plan view thereof; and,

FIG. 8 is an enlarged view of a hair straightener taken from the circle portion in FIG. 7.

The broken lines in the drawings depict portions of the hair straightener that form no part of the claimed design. The additional broken lines in FIGS. 7 and 8 are for purposes of annotating the enlarged view and form no part of the claimed design. 

CLAIM The ornamental design for a hair straightener, as shown and described. 